Study On Forest Vegetation Cover Changein Northeast China Border Area

Forests are not only the essential component of the earth's biosphere but also the main body of terrestrial ecosystems.The forest coverage rate can be regarded as a constraint indicator of economic and social development;hence,the dynamic changes of forest resources are valued by all the governments,while both the sustainable development of forest resources and obtaining accurate methods of forest cover change detection are particularly important.In this paper,the area near the northeastern border of China was chosen as the study area.Four phase Landsat images from 2002,2011,2013 and 2017 were obtained.Divided into two periods from 2002 to 2011 and 2013 to 2017.The iteratively weighted multivariate change detection algorithm was used to classify the change area and the IR-MAD(the iteratively reweighted multivariate alteration detection)was adopted in the non-change area.The algorithm which implemented and functioned the code on the Google Earth Engine cloud platform through the Docker toolbox,and then obtained the corresponding image processing in the ArcGIS and ENVI software.Finally it obtained the change detection map from 2002-2011 and 2013-2017,and explored the northeastern border of China.Regional forest coverage changed in time and space.Finally,Google Earth was adopted as the data source for image verification to evaluate the accuracy.The main content of the paper is as follows:(1)In the application of multivariate change detection method,the research on automatic detection of regional change information is one of the hot issues.This paper uses Google Earth Engine cloud platform for automatic detection and calculation.Explores more efficient detection methods,and adopts typical correlations.The iterative weighted multivariate change detection algorithm can effectively weaken the influence of background values and achieve high accuracy in the change regions.After verification,the detection accuracy of the two change region maps is all higher than 85%.(2)From the distribution of forest vegetation changes,the distribution of forest cover in the study area in the two periods of 2002-2011 and 2013-1017 was mainly located in the Far East region of Russia,and the loss of forest Coverage is the main part,and the change area is closer to the borderline,which is not conducive to border area ecological environment protection and the entity protection of the borders.(3)The dynamic rate of forest cover from 2002 to 2017 which averaged changed in the study area was 4.41%,the annual change rate in the first 10 years was 1.52%,and the annual change rate in the following five years was 1.03%.The annual change trend of forest cover gradually Slowing down,combined with ancillary analysis of highdefinition images,shows that the protection and sustainable development of forest resources in China is getting better and better.